266 resultados para perovskite phase
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The present study evaluated the potential of using the phase of T2* weighted MR images to characterize myelination during brain development and pathology in rodents at 9.4 T. Phase contrast correlated with myelin content assessed by histology and suggests that most contrast between white and cortical gray matter is modulated by myelin. Ex vivo experiments showed that gray-white matter phase contrast remains unchanged after iron extraction. In dysmyelinated shiverer mice, phase imaging correlated strongly with myelin staining, showing reduced contrast between white and gray matter when compared to healthy controls. We conclude that high-resolution phase images, acquired at high field, allow assessment of myelination and dysmyelination.
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BACKGROUND: Aromatase inhibitors provide superior disease control when compared with tamoxifen as adjuvant therapy for postmenopausal women with endocrine-responsive early breast cancer. PURPOSE: To present the design, history, and analytic challenges of the Breast International Group (BIG) 1-98 trial: an international, multicenter, randomized, double-blind, phase-III study comparing the aromatase inhibitor letrozole with tamoxifen in this clinical setting. METHODS: From 1998-2003, BIG 1-98 enrolled 8028 women to receive monotherapy with either tamoxifen or letrozole for 5 years, or sequential therapy of 2 years of one agent followed by 3 years of the other. Randomization to one of four treatment groups permitted two complementary analyses to be conducted several years apart. The first, reported in 2005, provided a head-to-head comparison of letrozole versus tamoxifen. Statistical power was increased by an enriched design, which included patients who were assigned sequential treatments until the time of the treatment switch. The second, reported in late 2008, used a conditional landmark approach to test the hypothesis that switching endocrine agents at approximately 2 years from randomization for patients who are disease-free is superior to continuing with the original agent. RESULTS: The 2005 analysis showed the superiority of letrozole compared with tamoxifen. The patients who were assigned tamoxifen alone were unblinded and offered the opportunity to switch to letrozole. Results from other trials increased the clinical relevance about whether or not to start treatment with letrozole or tamoxifen, and analysis plans were expanded to evaluate sequential versus single-agent strategies from randomization. LIMITATIONS: Due to the unblinding of patients assigned tamoxifen alone, analysis of updated data will require ascertainment of the influence of selective crossover from tamoxifen to letrozole. CONCLUSIONS: BIG 1-98 is an example of an enriched design, involving complementary analyses addressing different questions several years apart, and subject to evolving analytic plans influenced by new data that emerge over time.
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Background: Two or three DNA primes have been used in previous smaller clinical trials, but the number required for optimal priming of viral vectors has never been assessed in adequately powered clinical trials. The EV03/ANRS Vac20 phase I/II trial investigated this issue using the DNA prime/poxvirus NYVAC boost combination, both expressing a common HIV-1 clade C immunogen consisting of Env and Gag-Pol-Nef polypeptide. Methods: 147 healthy volunteers were randomly allocated through 8 European centres to either 3xDNA plus 1xNYVAC (weeks 0, 4, 8 plus 24; n¼74) or to 2xDNA plus 2xNYVAC (weeks 0, 4 plus 20, 24; n¼73), stratified by geographical region and sex. T cell responses were quantified using the interferon g Elispot assay and 8 peptide pools; samples from weeks 0, 26 and 28 (time points for primary immunogenicity endpoint), 48 and 72 were considered for this analysis. Results: 140 of 147 participants were evaluable at weeks 26 and/ or 28. 64/70 (91%) in the 3xDNA arm compared to 56/70 (80%) in the 2xDNA arm developed a T cell response (P¼0.053). 26 (37%) participants of the 3xDNA arm developed a broader T cell response (Env plus at least to one of the Gag, Pol, Nef peptide pools) versus 15 (22%) in the 2xDNA arm (P¼0.047). At week 26, the overall magnitude of responses was also higher in the 3xDNA than in the 2xDNA arm (similar at week 28), with a median of 545 versus 328 SFUs/106 cells at week 26 (P<0.001). Preliminary overall evaluation showed that participants still developed T-cell response at weeks 48 (78%, n¼67) and 72 (70%, n¼66). Conclusion: This large clinical trial demonstrates that optimal priming of poxvirus-based vaccine regimens requires 3 DNA regimens and further confirms that the DNA/NYVAC prime boost vaccine combination is highly immunogenic and induced durable T-cell responses.
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OBJECTIVES: Caspofungin was evaluated as first-line monotherapy of invasive aspergillosis (IA) in patients with haematological malignancies and undergoing autologous transplants. METHODS: Adults with proven or probable IA, defined strictly according to EORTC-MSG criteria, were eligible. Those with possible IA were enrolled, but were not evaluable for efficacy unless upgraded to proven/probable disease within 7 days of registration based on investigations performed within 48 h after enrolment. Caspofungin dosage was 70 mg (day 1) followed by 50 mg/day. The primary endpoint was the proportion of patients with complete or partial response at the end of caspofungin therapy in the modified intention to treat (MITT) group; secondary endpoints were response and survival at day 84 and safety. RESULTS: In the MITT group (n = 61), 75% of patients had cancer not in remission (relapsing or refractory), 85% were neutropenic at enrolment and 49% had a Karnofsky score of < or =50. At end of treatment, 1 and 19 patients had complete and partial response, respectively [success rate 33% (20/61)], 9 (15%) achieved stabilization and 31 (51%) had disease progression. One patient was not evaluable. The 6 and 12 week survival rates were 66% (40/61) and 53% (32/60), respectively. Baseline characteristics associated with survival at day 84 were an underlying disease in remission (not relapsing or refractory) and Karnofsky score. Recovery from neutropenia at the end of treatment was also significantly associated with survival. No serious drug-related adverse events or discontinuations due to drug-related adverse events were observed. CONCLUSIONS: Caspofungin provided an observed response rate compatible with the null hypothesis of a true response rate of < or =35%. Underlying disease-related factors had a major impact on results.
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BACKGROUND: Stage IIIB non-small-cell lung cancer (NSCLC) is usually thought to be unresectable, and is managed with chemotherapy with or without radiotherapy. However, selected patients might benefit from surgical resection after neoadjuvant chemotherapy and radiotherapy. The aim of this multicentre, phase II trial was to assess the efficacy and toxicity of a neoadjuvant chemotherapy and radiotherapy followed by surgery in patients with technically operable stage IIIB NSCLC. METHODS: Between September, 2001, and May, 2006, patients with pathologically proven and technically resectable stage IIIB NSCLC were sequentially treated with three cycles of neoadjuvant chemotherapy (cisplatin with docetaxel), immediately followed by accelerated concomitant boost radiotherapy (44 Gy in 22 fractions) and definitive surgery. The primary endpoint was event-free survival at 12 months. Efficacy analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00030810. FINDINGS: 46 patients were enrolled, with a median age of 60 years (range 28-70). 13 (28%) patients had N3 disease, 36 (78%) had T4 disease. All patients received chemotherapy; 35 (76%) patients received radiotherapy. The main toxicities during chemotherapy were neutropenia (25 patients [54%] at grade 3 or 4) and febrile neutropenia (nine [20%]); the main toxicity after radiotherapy was oesophagitis (ten patients [29%]; nine grade 2, one grade 3). 35 patients (76%) underwent surgery, with pneumonectomy in 17 patients. A complete (R0) resection was achieved in 27 patients. Peri-operative complications occurred in 14 patients, including two deaths (30-day mortality 5.7%). Seven patients required a second surgical intervention. Pathological mediastinal downstaging was seen in 11 of the 28 patients who had lymph-node involvement at enrolment, a complete pathological response was seen in six patients. Event-free survival at 12 months was 54% (95% CI 39-67). After a median follow-up of 58 months, the median overall survival was 29 months (95% CI 16.1-NA), with survival at 1, 3, and 5 years of 67% (95% CI 52-79), 47% (32-61), and 40% (24-55). INTERPRETATION: A treatment strategy of neoadjuvant chemotherapy and radiotherapy followed by surgery is feasible in selected patients. Toxicity is considerable, but manageable. Survival compares favourably with historical results of combined treatment for less advanced stage IIIA disease. FUNDING: Swiss Group for Clinical Cancer Research (SAKK) and an unrestricted educational grant by Sanofi-Aventis (Switzerland).
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NYVAC-C (vP2010), a recombinant vector expressing HIV subtype C gag, pol, env and nef antigens, was tested in a phase I study in healthy, HIV negative volunteers in London and Lausanne. Twenty-four participants were randomised to receive NYVAC-C (20) or matching placebo (4) at weeks 0 and 4, and assessed for safety and immunogenicity over 48 weeks. There were no serious adverse events, and no clinical or laboratory abnormalities or other events that led to withdrawal, interruption or dose reduction of the NYVAC-C/placebo. Half of the 10 assessed responded in the ELISpot assay under stringent criteria, which informed the sample size for a DNA-NYVAC-C comparison to NYVAC-C alone.
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Background The superiority of a chemotherapy with doxorubicin, cyclophosphamide, vindesine, bleomycin and prednisone (ACVBP) in comparison with cyclophosphamide, doxorubicin, vincristin and prednisone plus radiotherapy for young patients with localized diffuse large B-cell lymphoma (DLBCL) was previously demonstrated. We report the results of a trial which evaluates the role of rituximab combined with ACVBP (R-ACVBP) in these patients. Patients and methods Untreated patients younger than 66 years with stage I or II DLBCL and no adverse prognostic factors of the age-adjusted International Prognostic Index were randomly assigned to receive three cycles of ACVBP plus sequential consolidation with or without the addition of four infusions of rituximab. Results A total of 223 patients were randomly allocated to the study, 110 in the R-ACVBP group and 113 in the ACVBP group. After a median follow-up of 43 months, our 3-year estimate of event-free survival was 93% in the R-ACVBP group and 82% in the ACVBP group (P = 0.0487). Three-year estimate of progression-free survival was increased in the R-ACVBP group (95% versus 83%, P = 0.0205). Overall survival did not differ between the two groups with a 3-year estimates of 98% and 97%, respectively (P = 0.686). Conclusion In young patients with low-risk localized DLBCL, rituximab combined with three cycles of ACVBP plus consolidation is significantly superior to ACVBP plus consolidation alone.
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We present a combined shape and mechanical anisotropy evolution model for a two-phase inclusion-bearing rock subject to large deformation. A single elliptical inclusion embedded in a homogeneous but anisotropic matrix is used to represent a simplified shape evolution enforced on all inclusions. The mechanical anisotropy develops due to the alignment of elongated inclusions. The effective anisotropy is quantified using the differential effective medium (DEM) approach. The model can be run for any deformation path and an arbitrary viscosity ratio between the inclusion and host phase. We focus on the case of simple shear and weak inclusions. The shape evolution of the representative inclusion is largely insensitive to the anisotropy development and to parameter variations in the studied range. An initial hardening stage is observed up to a shear strain of gamma = 1 irrespective of the inclusion fraction. The hardening is followed by a softening stage related to the developing anisotropy and its progressive rotation toward the shear direction. The traction needed to maintain a constant shear rate exhibits a fivefold drop at gamma = 5 in the limiting case of an inviscid inclusion. Numerical simulations show that our analytical model provides a good approximation to the actual evolution of a two-phase inclusion-host composite. However, the inclusions develop complex sigmoidal shapes resulting in the formation of an S-C fabric. We attribute the observed drop in the effective normal viscosity to this structural development. We study the localization potential in a rock column bearing varying fraction of inclusions. In the inviscid inclusion case, a strain jump from gamma = 3 to gamma = 100 is observed for a change of the inclusion fraction from 20% to 33%.
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Proteins disabled in Fanconi anemia (FA) are necessary for the maintenance of genome stability during cell proliferation. Upon replication stress signaling by ATR, the FA core complex monoubiquitinates FANCD2 and FANCI in order to activate DNA repair. Here, we identified FANCD2 and FANCI in a proteomic screen of replisome-associated factors bound to nascent DNA in response to replication arrest. We found that FANCD2 can interact directly with minichromosome maintenance (MCM) proteins. ATR signaling promoted the transient association of endogenous FANCD2 with the MCM2-MCM7 replicative helicase independently of FANCD2 monoubiquitination. FANCD2 was necessary for human primary cells to restrain DNA synthesis in the presence of a reduced pool of nucleotides and prevented the accumulation of single-stranded DNA, the induction of p21, and the entry of cells into senescence. These data reveal that FANCD2 is an effector of ATR signaling implicated in a general replisome surveillance mechanism that is necessary for sustaining cell proliferation and attenuating carcinogenesis.
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Solid phase microextraction (SPME) has been widely used for many years in various applications, such as environmental and water samples, food and fragrance analysis, or biological fluids. The aim of this study was to suggest the SPME method as an alternative to conventional techniques used in the evaluation of worker exposure to benzene, toluene, ethylbenzene, and xylene (BTEX). Polymethylsiloxane-carboxen (PDMS/CAR) showed as the most effective stationary phase material for sorbing BTEX among other materials (polyacrylate, PDMS, PDMS/divinylbenzene, Carbowax/divinylbenzene). Various experimental conditions were studied to apply SPME to BTEX quantitation in field situations. The uptake rate of the selected fiber (75 μm PDMS/CAR) was determined for each analyte at various concentrations, relative humidities, and airflow velocities from static (calm air) to dynamic (>200 cm/s) conditions. The SPME method also was compared with the National Institute of Occupational Safety and Health method 1501. Unlike the latter, the SPME approach fulfills the new requirement for the threshold limit value-short term exposure limit (TLV-STEL) of 2.5 ppm for benzene (8 mg/m3).
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Multi-phase postmortem CT angiography (MPMCTA) is recognized as a valuable tool to explore the vascular system, with higher sensitivity than conventional autopsy. However, a limitation is the impossibility to diagnose pulmonary embolism (PE) due to post-mortem blood clots situated in pulmonary arteries. The purpose of this study was to explore an eventual possibility to distinguish between real PE and artefacts mimicking PE. Our study included 416 medico-legal cases. All of them underwent MPMCTA, conventional autopsy and histological examination. We selected cases presenting arterial luminal filling defects in the pulmonary arteries. Their radiological interpretation was confronted to the one of autopsy and histological examination. We also investigated an eventual correlation between artefacts in pulmonary arteries and those in other parts of the vascular system. In 123 cases, filling defects of pulmonary arteries were described during MPMCTA. In 57 cases, this was interpreted as artefact and in 4 cases as suspected PE. In 62 cases only a differential diagnosis was made. Autopsy and histology could clearly identify the artefacts as such. Only one case of real PE was radiologically misinterpreted as artefact. In 6 of the 62 cases with no interpretation a PE was diagnosed. In 3 out of 4 suspected cases, PE was confirmed. We found out that filling defects in pulmonary arteries are nearly always associated to other vascular artefacts. Therefore, we suggest following some rules for radiological interpretation in order to allow a reliable diagnosis of pulmonary embolism after MPMCTA.
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Pegfilgrastim is equivalent to daily filgrastim after standard dose chemotherapy in decreasing the duration of neutropenia. Daily filgrastim started within 1-4 days after autologous stem cell transplant (ASCT) leads to significant decrease in time to neutrophil engraftment. We undertook a study of pegfilgrastim after high-dose chemotherapy (HDC) and ASCT. In all, 38 patients with multiple myeloma or lymphoma, eligible to undergo HDC and ASCT, were enrolled. Patients received a single dose of 6 mg pegfilgrastim subcutaneously 24 h after ASCT. There were no adverse events secondary to pegfilgrastim. All patients engrafted neutrophils and platelets with a median of 10 and 18 days, respectively. The incidence of febrile neutropenia was 49% (18/37). Neutrophil engraftment results were compared to a historical cohort of patients who received no growth factors or prophylactic filgrastim after ASCT. Time to neutrophil engraftment using pegfilgrastim was comparable to daily filgrastim and was shorter than in a historical group receiving no filgrastim (10 vs 13.7 days, P<0.001). Pegfilgrastim given as a single fixed dose of 6 mg appears to be safe after HDC and ASCT. It accelerates neutrophil engraftment comparable to daily filgrastim after ASCT. Pegfilgrastim may be convenient to use in outpatient transplant units.
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This trial was aimed to explore the efficacy of pegfilgrastim to accelerate neutrophil engraftment after stem cell autotransplant. Twenty patients with multiple myeloma and 20 with lymphoma received pegfilgrastim 6 mg on day +1. Forty cases treated with daily filgrastim starting at median day +7 (5-7), matched by age, sex, diagnosis, high-dose chemotherapy schedule, CD34 + cell-dose, and prior therapy lines, were used for comparison. Median time to neutrophil engraftment was 9.5 vs. 11 days for pegfilgrastim and filgrastim, respectively (p < 0.0001). Likewise, duration of neutropenia, intravenous antibiotic use, and hospitalization favored pegfilgrastim, while platelet engraftment, transfusion requirement, and fever duration were equivalent in both groups. No grade ≥ 3 toxicities were observed. Patients with lymphoma performed similarly to the entire cohort, while patients with myeloma showed faster neutrophil engraftment and shorter neutropenia but not shorter hospitalization and antibiotic use. The possibility of different outcomes for lymphoma and myeloma suggests that stratification by diagnosis may be useful in future phase III studies.